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Visual system function requires translational regulation of ATF4 by Hbs1-Pelo
Katherine Tempro1, Inês Lago-Baldaia2, Narayanan Nampoothiri V P1
1Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, USA.
EMBO Reports
|July 17, 2026
Summary
Deletion mutations in HBS1L cause vision loss. This study shows Hbs1-Pelo regulates phototransduction in lamina neurons by controlling ATF4 levels, offering insight into inherited retinal disease.
Area of Science:
- Neuroscience
- Genetics
- Cell Biology
Background:
- HBS1L mutations cause vision loss and developmental issues.
- The precise mechanisms behind HBS1L-associated vision defects are unknown.
Purpose of the Study:
- To investigate the role of HBS1L and its ortholog Hbs1 in the visual system.
- To elucidate the molecular mechanisms underlying HBS1L-related inherited retinal diseases.
Main Methods:
- Utilized the Drosophila visual system to study Hbs1 and Pelo function.
- Performed genetic manipulations (mutants, depletion) in Drosophila.
- Investigated molecular pathways involving Activating Transcription Factor 4 (ATF4) in Drosophila and human cell cultures.
Main Results:
- Hbs1 and Pelo are essential for phototransduction in Drosophila.
- Hbs1 mutants exhibit vacuolization in the lamina, indicating impaired synapse transmission.
- Loss of HBS1L/Hbs1 leads to reduced ATF4 levels, and restoring ATF4 partially rescues visual defects.
Conclusions:
- Hbs1-Pelo complex is crucial for lamina neuron function and phototransduction.
- Hbs1-Pelo regulates ATF4 translation, which is implicated in inherited retinal disease.
- This study proposes a model where Hbs1-Pelo-mediated ATF4 regulation in lamina neurons causes vision loss in HBS1L deletion patients.
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